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Problems with S/PDIF
Posted: Fri Sep 21, 2007 12:52 am
by motormind
I have a Scope Professional card under Windows XP, but can't get the card's S/PDIF input to work properly with either my Bass Pod Pro or my Akai MPC-1000.
With the POD, it only works when I set the card to slave mode. If I don't do that, I get ticks in stereo. Very weird. In master mode, the MPC1000 sounds distorted. In slave mode it works better, but I get intermittent drop outs every few seconds.
I always set all of the sample rates to 44100 Hz, no mater which mode I use. Does anyone else recognize these problems? Thanks in advance for any input.
Posted: Fri Sep 21, 2007 1:35 am
by garyb
there's no problem.
there can only be one mater clock. you have two devices with clocks(scope and basspod or mpc). clock is transmitted from the output of one device to the input of the other.
if scope is master, how does the pod recieve clock so that the data from both devices will be in sync? is there an sp/dif input so that clock can go from scope to the pod, and is there a way to make the pod slave?
if you only have an sp/dif output from a device connected to your scope card, scope MUST be slave for there to only be one clock(unless everything, both scope and the other device, is slaved to bnc wordclock).
Posted: Fri Sep 21, 2007 1:45 am
by motormind
garyb wrote:there's no problem.
there can only be one mater clock. you have two devices with clocks(scope and basspod or mpc). clock is transmitted from the output of one device to the input of the other.
if scope is master, how does the pod recieve clock so that the data from both devices will be in sync? is there an sp/dif input so that clock can go from scope to the pod, and is there a way to make the pod slave?
if you only have an sp/dif output from a device connected to your scope card, scope MUST be slave for there to only be one clock(unless everything, both scope and the other device, is slaved to bnc wordclock).
That still doesn't explain why I get those dropouts with the MPC1000. I also had no problems whatsoever when I still used my Terratec...
Posted: Fri Sep 21, 2007 2:56 am
by Mr Arkadin
Don't know about the MPC but setting Scope to slave to my Podxt Pro was the only way i could get that to work.
Posted: Fri Sep 21, 2007 10:33 am
by garyb
motormind wrote:That still doesn't explain why I get those dropouts with the MPC1000. I also had no problems whatsoever when I still used my Terratec...

i've explained how it works......
Posted: Fri Sep 21, 2007 3:08 pm
by valis
This is a limitation of the SPDIF format, which is really a consumer format. External devices will almost always want to be 'master', as that is how the specification is defined.
The problems with your MPC could be related to using a cable of the wrong impedence (normal 'phono' / rca style plugs will 'seem' to work but are actually the wrong impedence), just a bad cable or perhaps even an issue with the MPC. The cable impedence would be my first choice of things to solve, as gear will vary in how the spdif electrics are implemented. One piece of gear will 'seem' to work with improper cables and yet another will have problems...sounds fitting to your post imo.
Posted: Sun Sep 23, 2007 12:53 am
by motormind
valis wrote:This is a limitation of the SPDIF format, which is really a consumer format. External devices will almost always want to be 'master', as that is how the specification is defined.
The problems with your MPC could be related to using a cable of the wrong impedence (normal 'phono' / rca style plugs will 'seem' to work but are actually the wrong impedence), just a bad cable or perhaps even an issue with the MPC. The cable impedence would be my first choice of things to solve, as gear will vary in how the spdif electrics are implemented. One piece of gear will 'seem' to work with improper cables and yet another will have problems...sounds fitting to your post imo.
I use special digital RCA cables with the proper impendance, so that's not it. Also, when the sound drops out with the MPC-1000 I get an hour glass in SCOPE. AGain, I never had these issues with my ol' Terratec card, so I wonder what's up.
Posted: Sun Sep 23, 2007 1:20 am
by garyb
bad connector on the mpc?
if it works with one device, i wouldn't think the card was broken, although i guess that's always a possibility. the sp/dif input does work properly on scope cards, generally.
Posted: Sun Sep 23, 2007 4:16 am
by studioblabla
I made a cd with a band with the best drummer and bassplayer a ever had in the studio, mr DR-880 from boss
spdif to scope, nope... changed cables and bought digital cables. (tried normal, 50 OHM and 75 OHM calbes. I think it should be 75 OHM video coax?)
spdif to my motu 2408 MKII: sound with clicks. (master is boss and slave scope or motu)
spdif to my tc m3000: SOUND!
so the M3000 in bypass mode and spdif of the m3000 to scope and recording ok in the computer!
Any explanation?
Bart
Posted: Sun Sep 23, 2007 11:53 am
by garyb
no.....
glad you made it work....